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Need a larger electric service?

TimNY

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Joined
Jan 13, 2010
Messages
1,133
Location
Charleston, SC
An existing A-3 occupancy (existing for many decades) has continually increased their electrical demands to a point where the existing service cannot adequately supply the loads.

The current service is 200A. The solution that they came up with is to add a 100kw generator outside.

Electric is not my thing, but there are other issues (zoning, planning). My question is whether or not there is any requirement that the service be adequate to furnish the loads, or is this is a viable alternative?

Seems odd to me, but I know some large facilities have cogeneration. Would there be a difference if it were permanent versus something on wheels?

Thanks,

Tim
 
How is a generator less expensive than a service upgrade after all of the wiring and switchgear that goes with it?
 
= : = : =

What codes are you using ?

According to the `08 NEC, use of a generator is permitted [ RE: Article 90.2 - Scope ]

If this option is selected, there are a lot of design issues to develop BEFORE simply

purchasing a generator and installing it [ i.e. - sizing of conductors, ...safety switches,

...where is the generator intended for, ...are the existing conductors & circuit breakers

sized properly to accommodate this additional generator load, ...what happens if the

existing utility electrical service is lost = "backfeeding", and on and on and on ].

Agree with **Frank**, ...rewiring and upgrading everything on the site would be far

less cheaper in the long run.

= : = : =

 
cda said:
So is the generator for stand byOr to augment???
As explained to me, to augment.

Frank said:
How is a generator less expensive than a service upgrade after all of the wiring and switchgear that goes with it?
Yeah, my thoughts exactly. Apparently this is cheaper (building is leased). Which brings me to the last question I had.. whether it is permanent or portable. They could rent something for the summer season and plug it in with an umbilical. Probably cheap. Probably not compliant.

north star said:
= : = : =What codes are you using ?

According to the `08 NEC, use of a generator is permitted [ RE: Article 90.2 - Scope ]

If this option is selected, there are a lot of design issues to develop BEFORE simply

purchasing a generator and installing it [ i.e. - sizing of conductors, ...safety switches,

...where is the generator intended for, ...are the existing conductors & circuit breakers

sized properly to accommodate this additional generator load, ...what happens if the

existing utility electrical service is lost = "backfeeding", and on and on and on ].

Agree with **Frank**, ...rewiring and upgrading everything on the site would be far

less cheaper in the long run.

= : = : =

Yes, 2008 NEC. THanks for the input.

Apparently they have retained an engineer and contractor to work this out and it is the better solution. I am a bit skeptical, but as long as it complies it's fine with me.

Tim
 
= : = : =

Can you further define "augment" ?

If a generator is added to augment an increased power demand, will the

existing elec. systems be able to safely & compliantly handle the load ?

I'm thinking not !........Sounds like some additional wiring & systems

installations are in the future.

FWIW, ...just because an engineer & contractor are already

involved does not necessarily mean that their solution will be a cheaper

solution to the owners.......[ IMO ] Their proposals should be very

carefully scrutinized, by someone competent.



= : = : =
 
TimNY said:
As explained to me, to augment.Yeah, my thoughts exactly. Apparently this is cheaper (building is leased). Which brings me to the last question I had.. whether it is permanent or portable. They could rent something for the summer season and plug it in with an umbilical. Probably cheap. Probably not compliant.

Yes, 2008 NEC. THanks for the input.

Apparently they have retained an engineer and contractor to work this out and it is the better solution. I am a bit skeptical, but as long as it complies it's fine with me.

Tim
Not an electrician , but how to you wire an electrical system to use city power and a generator at the same time???
 
north star said:
= : = : =Can you further define "augment" ?

If a generator is added to augment an increased power demand, will the

existing elec. systems be able to safely & compliantly handle the load ?

I'm thinking not !........Sounds like some additional wiring & systems

installations are in the future.

FWIW, ...just because an engineer & contractor are already

involved does not necessarily mean that their solution will be a cheaper

solution to the owners.......[ IMO ] Their proposals should be very

carefully scrutinized, by someone competent.



= : = : =
In process of trying to get further information. There are other zoning/planning issues that may eventually weigh heavier than the cost.

cda said:
Not an electrician , but how to you wire an electrical system to use city power and a generator at the same time???
Not an electrician either.. I know it's done (ie our hospital does it). I've never seen it otherwise simply because it's not cost effective.

I am wondering if they are just going to transfer some loads to the generator-- like disconnect the air conditioning units from the service and run them off of the generator instead, thereby lessening the load on the poco service. Just guessing at this point. I will let you know when I hear more.

Tim
 
"""Not an electrician either.. I know it's done (ie our hospital does it). I've never seen it otherwise simply because it's not cost effective.""""

Yes as a back up generator

But not to run appliances constantly day to day operations
 
"""Not an electrician either.. I know it's done (ie our hospital does it). I've never seen it otherwise simply because it's not cost effective.""""

Yes as a back up generator

But not to run appliances constantly day to day operations

Tim just a question ,,, what do you do for a living??
 
Alot of high importance buildings here have generators and go "off grid" during peak demand.....but it is typically all or nothing....and for an hour or so....Sounds like they would be treating the genny as a second service?
 
cda said:
"""Not an electrician either.. I know it's done (ie our hospital does it). I've never seen it otherwise simply because it's not cost effective.""""Yes as a back up generator

But not to run appliances constantly day to day operations
No, not as backup. They cogenerate with the local power utility. The thing looks like a locomotive in the basement.

Tim
 
TimNY said:
The thing looks like a locomotive in the basement.
The installation has begun?

I am an electrician and fail to so how this could me more cost effective than a service upgrade. Mind boggling.
 
chris kennedy said:
The installation has begun?I am an electrician and fail to so how this could me more cost effective than a service upgrade. Mind boggling.
No, not this installation. I think we were talking about the hospital. Or at least I was talking about it. I think that is what cda was referencing. The local hospital (not in my jurisdiction, but I have been through the building) has a generator the size of a locomotive in the basement that cogenerates. It was explained to me that it runs 24/7. It was running when I was there and even with hearing protection it was deafening. Again, not my jurisdiction so I don't have the inside line on it, but that is how it was explained to me by the plant manager.

The project in my jurisdiction has not begun yet. I am just on a fact finding mission before we go to planning. The first quesiton being can they add a generator to satisfy the load of permanently installed equipment rather than upgrading the service, which by all accounts is 'yes'.

That brings me the the question of whether or not they can just call up United Rentals, have them wheel up a 100kw generator and start wiring or is there some other aspect I have to look at.

Hey, what if it's in a flood plain (it is)?

Beyond that I'll get some details just because I hate when people ask questions and you never hear about what happens ;)

Tim
 
TimNY said:
Beyond that I'll get some details just because I hate when people ask questions and you never hear about what happens ;)

Tim
If you could post a riser diagram that would be great.

Burning question in my mind, how did additional loads get added over the years that did not comply with NEC 220 that now requires a service upgrade or co-generation???
 
Before my time, but I'm guessing years of nobody getting permits and nobody at the government level actually caring.I had another situation dropped on my lap today with 4 meters and 4 panels in a closet about 16" deep with a 30" door. The service drop is tapped for those meters and tapped again for a meter on the outside of the building. Nobody knows how that happened, either.Tim
governments-in-a-nutshell_gp_2031791.jpg


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I would also check with the local electricity provider

I am sure they have quite abit to say on the subject
 
steveray said:
Alot of high importance buildings here have generators and go "off grid" during peak demand.....but it is typically all or nothing....and for an hour or so....Sounds like they would be treating the genny as a second service?
Our office here has full capacity standby generators and we are on "interruptable" power with the power company. The rate savings paid for the generator installation over a number of years.
 
Just got off the phone and my head is spinning.

They want to patch a portion of the existing load into the generator, which is being delivered shortly. It will be leased for the next few months.

No permit necessary, they thought. Just a few twistlocks and flexible cords, why could they possibly need a permit?

More to come.

Tim
 
Around here there is an agency called Air Quality Management District. A permit from AQMD is required for a fuel burning generator. Good luck with that.

The scenario of a 200 amp service augmented with a generator is weird.
 
1. Contact local electric provider

2. Require a permeant circuit breaker panel attached to the building, that may make the generator go away,,,

Besides saying NO to begin with.
 
All good suggestions, thanks.

Apparently POCO is on board. It's a business district and the spec for the generator substantiate compliance with decibels permitted at night. We don't have any air quality regulations other than a blanket 'shall not cause a nuisance' ordinance.

Wiring diagram is supposed to be furnished soon. Will report back.

Tim
 
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